Red azo dye and process of making same.



' UNITED STATES PATENT OFFICE.

FELIX KLINGEMANN AND GEORG KALISCHER, OF FRANKFORT-ON-THE- MAIN, GERMANY, ASSIGNORS TO OASSELLA COLOR OOMPANY, OF NEWV YORK, N. Y.

Specification of Letters Patent.

Patented Dec. 12, 1905.

Application filed August 21, 1905. Serial No. 275,166.

To all whom it may concern.-

Be it known that we, FELIX KLINGEMANN' and GEoRG KALISCHER, doctors of philosophy, citizens of Prussia, and residents of Frankfort-on-the-Main, in the Province of Hesse- Nassau and Kingdom of Prussia, Germany, have invented certain new and useful Improvements in the Process of Making Red Azo Dyes, of which the following is a specification.

Our presentinvention is based upon our discovery that the monoazo dyes formed by combining the diazo compounds of aromatic amidoaldehydes with the sulfo acids of alpha and ness to washing and to acids.

beta naphthol can be condensed in acid solution with the 1-2-diamido-naphthalene-5-hydroxy- 7.sulfonic acid in the proportion of two molecules to one to form the diazo coloring-matters of the following constitution,

yellowish red to a bluish red, according to the naphtholsulfonic acid and to the diazo compound used in the preparation of the dyestuff. They have a strong affinity for cotton. The dyes obtained with them are of great fast- In the dry state they represent powders of a reddish-brown shade. They are soluble in water with a red color. Acids precipitate the dyestuffs from these solutions.

The following example will serve to further illustrate the manner in which our invention can be carried out. The parts are by weight: 24.2 parts of meta-amidobenzaldehyde are diazotized in the usual manner with seventy parts of hydrochloric acid of 20 Baum and fourteen parts of sodium nitrite. The cold diazo solution is poured into the cold solution of fifty parts of the sodium salt of 2.6-naphtholsulfonic acid and of sixty parts of dry sodium carbonate. The dyestuff is filtered off and is dissolved in one thousand parts of boiling water. To this solution is added the solution of 25.4 parts of 1.2.diamidonaphthalene5.hydroxy.7-sulfonic acid with fourteen parts of sodium acetate. The mixture being boiled for half an hour is then acidified by means of hydrochloric acid, and the boiling is continued for half an hour. The red precipitate thus formed is filtered off and is dissolved in two thousand four hundred parts of boiling water, to which are added forty parts of dry sodium carbonate. The solution is cooled down with ice, and the diazo compound formed by diazotizing 9.3 parts of anilin with thirty-five parts of hydrochloric acid and seven parts of sodium nitrite is then allowed to run in. The coloring-matter is formed in a few minutes. As soon as the diazo compound has disappeared the solution is lightly heated and the coloring-matter separated by common salt. It is filtered off, pressed, and dried.

Instead of the 2.6.naphtholsulfonic acid other mono or disulfonic acids of alpha or beta naphthol may be used. The anilin may be substituted by other aromatic bases.

Instead of condensing one molecule of 1.2-

diamido-5-hydroxy-7-sulfonic acid with two molecules of the same aldehydeazo dye two molecules of two difierent aldehydeazo dyestuffs may be used. Thus one molecule of 1-2-diamidonaphthalene-5-h ydroXy-7-sulfonic acid can be condensed with one molecule of the dyestuff prepared from metaamido-benzaldehyde and 2-6-naphtholsulfonic acid and with one molecule of the azo dye prepared from meta-amido-benzaldehyde and l- L-naphtholsulfonic acid. This condensation product can then be combined in alkaline solution with one molecule of an aromatic diazo compound, such as diazo-benzene, diazo-ortho toluene, &c.

Having now described our invention and the manner of performing the same, what we claim is 1. The herein-described process of making disazo dyestuifs, which consists in condensing in aqueous solution one molecule of 1.2-diamidonaphthalene-5-hydroxy-7-sulfonic acid with two molecules of a monoazo dyestuif prepared from the diazo compound of metaamido-ben'- zaldehyde and a naphtholsulfonic acid in the manner hereinbefore described, substantially as described.

2. The herein-described process of making disazo dyestuffs, which consists in condensing in aqueous solution one molecule of 1-2-diamidonaphthalene-5-hydroXy-7-sulfonio acid with two molecules of two different monoazo dyestuffs prepared from the diazo compound of meta-amido-benzaldehyde and a naphtholsulfonic acid in the manner hereinbefore described, substantially as described.

3. The herein-described process of making trisazo dyestufis, which consists in combining an aromatic diazo compound in alkaline solution with the products obtained by condensing in aqueous solution one molecule of 1-2-diamidonaphthalene5-hydroXy7-sulfonic acid with 4 two molecules of a monoazo dyestufi containing an aldehyde group, the latter being formed by combining one molecule of diazotized metaamido-benzaldehyde with one molecule of a naphtholsulfonic acid, substantially as described. g

4. The trisazo coloring-matters obtained by combining in an alkaline solution one molerepresenting in the dry state powders of a reddish-brown shade, soluble in water with a red color, dissolving in concentrated sulfuric -ac1d with a blulsh-red color which changes into a more yellowish shade by adding water, and dyeing unmordanted cotton red shades, substantially as described.

Signed at Frankfort on the Main, in the Province of Hesse-Nassau and Kingdom of Prussia, Germany, this 31st day of July, A. D. 1905.

FELIX KLINGEMANN. GEORG KALl SOHER.

Witnesses:

JEAN GRUND, CARL GRUNI). 

